Copolymers containing styrene oxide and use thereof as emulsifiers and dispersing agents

ABSTRACT

The invention relates to copolymers of formula (I) wherein R 1  is hydrogen, a C 1 -C 5 -alkyl radical or C 2 -C 5 -alkenyl radical which can also contain heteroatoms, an acid group or an aliphatic or aromatic group comprising 1-50 carbon atoms, including an acid group, R 2  and R 3  independently represent hydrogen, methyl and/or ethyl, n ranges from 0-100, and m ranges from 3 to 30, and k ranges from 1-200, and A is hydrogen, an acid group, a C 1 -C 5 -alkyl radical or a C 2 -C 8 -alkenyl radical which can also contain heteroatoms, an aliphatic or aromatic group comprising 1-50 carbon atoms, including an acid group, or a copolymer unit of formula (II), wherein R 4  is hydrogen, a C 1 -C 5 -alkyl radical or a C 2 -C 5 -alkenyl radical which can also contain heteroatoms, an acid group or an aliphatic or aromatic group comprising 1-50 carbon atoms, including an acid group, R 5  is hydrogen, methyl and/or ethyl, x ranges from 0 to 100, and y ranges from 3-30, wherein, if A is formula (2), R 1  represents hydrogen or an acid group.

The present invention relates to nonionic and anionic emulsifiers forpigments, bitumen and the emulsion polymerization which containcopolymers of alkylene oxides and styrene oxide.

The emulsifiers used for dispersing bitumen and pigments or for theemulsion polymerization according to the prior art are generally anionicand nonionic emulsifiers.

Customary anionic emulsifiers are sodium, potassium and ammonium saltsof fatty acids, sodium alkylbenzenesulfonates, sodium alkanesulfonates,sodium olefinsulfonates, sodium polynaphthalenesulfonates, sodiumdialkyldiphenyl ether disulfonates, sodium, potassium and ammoniumalkylsulfates, sodium, potassium and ammonium alkylpolyethylene glycolether sulfates, sodium, potassium and ammonium alkylphenol polyethyleneglycol ether sulfates, sodium, potassium and ammonium mono- anddialkylsulfosuccinates and monoalkyl polyoxyethylsulfosuccinates, andalkylpolyethylene glycol ether phosphoric acid mono-, di- and triestersand mixtures thereof and alkylphenol polyethylene glycol etherphosphoric acid mono-, di- and triesters and mixtures thereof, andsodium, potassium and ammonium salts thereof.

Nonionic emulsifiers usually used are alkylphenol polyethylene glycolethers, alkylpolyethylene glycol ethers, fatty acid polyethylene glycolethers, ethylene/propylene glycol block polymers and sorbitan esterpolyethylene glycol ethers.

Very good emulsifying properties can be achieved by the use of ethyleneoxide/propylene oxide polymers having nonylphenols as a hydrophobic headgroup. WO 00/04096 discloses the use of such nonylphenol alkoxylates asdispersing agents for bitumen emulsions. However, since the nonylphenolgroup has fallen into disrepute owing to its unfavorableecotoxicological properties, alternatives for it are being sought.

EP-A-0 403 718 discloses alkyl ether styrene oxide alkoxylates havingone terminal alkyl ether styrene oxide unit each on the polyalkoxylatechains.

EP-A-1 078 946 discloses C₈-C₁₃-alkyl ether styrene oxide alkoxylates.

Both applications disclose copolymers having from one to not more thantwo units of styrene oxide and the use thereof inunreactive/noncopolymerizable systems.

Particularly in the area of emulsion polymerization, copolymerizableemulsifiers have attracted particular interest in the recent past, i.e.those which have a double bond which can react in a free radicalpolymerization.

J. Polym. Sci., 30 (1992) 2619-2629 and J. Polym. Sci., 31 (1993)1403-1415 describe, for example, the use of sodiumdodecylallylsulfosuccinate as a copolymerizable emulsifier in theemulsion polymerization of vinyl acetate.

EP-A-050 166 describes aqueous polymer dispersions which were preparedby emulsion polymerization using emulsifiers capable of free radicalpolymerization.

EP-A-0 472 837 describes 1-propenyl alkylphenolethoxylates asemulsifiers for emulsion polymerization.

EP-A-0 464 454 describes sulfuric esters of 1-propenylalkylphenolethoxylates as emulsifiers for emulsion polymerization.

It is therefore an object of the present invention to providesubstitutes for nonylphenol alkoxylates having outstanding emulsifyingand dispersing properties, which can easily be made available both innonpolymerizable form and in polymerizable form, and whose molecularstructure can be easily and flexibly adapted to the medium to bedispersed in each case.

It has now been found that outstanding dispersing properties can beachieved with copolymers of alkylene oxides and styrene oxide. In thearea of pigment and bitumen dispersions, in particular unreactivecopolymers having a plurality of condensed units of styrene oxide can beused. In the area of emulsion polymerization, vinyl ether or allyl etherpolystyrene oxide alkoxylates can be used as copolymerizableemulsifiers.

The invention therefore relates to copolymers of the formula (1)

in which

-   R¹ is hydrogen, a C₁-C₅-alkyl radical, or C₂-C₅-alkenyl radical    which may also contain hetero atoms, an acid group or an aliphatic    or aromatic group having 1 to 50 carbon atoms, which carries an acid    group,-   R² and R³ independently of one another, are hydrogen, methyl and/or    ethyl,-   n is a number from 0 to 100, and-   m is a number from 3 to 30, and-   k is a number from 1 to 200, and-   A is hydrogen, an acid group, a C₁-C₅-alkyl radical or C₂-C₈-alkenyl    radical which may also contain hetero atoms, an aliphatic or    aromatic group having 1 to 50 carbon atoms, which carries an acid    group, or a copolymer unit of the formula (2)

in which

-   R⁴ is hydrogen, a C₁-C₅-alkyl radical or C₂-C₅-alkenyl radical which    may also contain hetero atoms, an acid group or an aliphatic or    aromatic group having 1 to 50 carbon atoms, which carries an acid    group,-   R⁵ is hydrogen, methyl and/or ethyl,-   x is a number from 0 to 100, and-   y is a number from 3 to 30,    where, if A corresponds to formula (2), R¹ is hydrogen or an acid    group.

The invention furthermore relates to a process for carrying out anemulsion polymerization by adding the copolymers according to theinvention to a reaction mixture to be polymerized.

The invention furthermore relates to a process for the preparation ofpolymer dispersions by polymerizing the copolymers according to theinvention with olefinically unsaturated monomers in the aqueous phase,and the aqueous polymer dispersion which can be prepared in this manner.

The invention furthermore relates to a process for dispersing pigmentsor bitumen by adding the copolymers according to the invention to thepigments or to the bitumen.

The invention furthermore relates to the use of the copolymers accordingto the invention as emulsifiers in emulsion polymerization or as pigmentand bitumen emulsifier.

If the copolymers according to the invention are used as emulsifiers inemulsion polymerization, they contain an olefinic double bond. In thiscase, R¹ or R⁴ is a C₂- to C₅-alkenyl group, or A is an olefinicallyunsaturated carboxylic acid.

The repetitive structural units in formulae 1 and 2 can be arrangedrandomly or block by block. In a preferred embodiment of the invention,the copolymers according to the invention are those alkoxylates whosealkoxy groups are arranged block by block.

k in a preferred embodiment is a number from 10 to 100.

m in a preferred embodiment is a number from 3 to 10.

n in a preferred embodiment is a number from 1 to 5.

In a preferred embodiment of the invention, the formula 1 represents anester or partial ester. Examples of inorganic acids which are suitablefor the formation of the partial esters according to the invention andfrom which A, R⁴ or R¹ may be derived are sulfuric acid and phosphoricacid. If phosphoric acid is used, the partial esters according to theinvention may be either monoesters or diesters of phosphoric acid. If Ais an acid radical, it can be bonded to the copolymer by means of ahydrocarbon group of 1 to 50 carbon atoms.

In a preferred embodiment, the organic or inorganic acids used for theesterification of the copolymers according to formula 1 are monobasic,dibasic or tribasic.

In a preferred embodiment, the organic acids are monobasic, dibasic,tribasic or polybasic carboxylic acids. Monobasic acids are preferablyan unsaturated carboxylic acid, such as, for example, acrylic acid,methacrylic acid, crotonic acid, itaconic acid, maleic acid or fumaricacid. Dibasic, tribasic or polybasic carboxylic acids are compoundswhich contain 2, 3 or more carboxyl groups and which moreover may haveat least one sulfur- or phosphorus-containing functional group.Sulfur-containing functional groups are particularly preferred,especially sulfonate groups.

The particularly preferred sulfonic acids/sulfonates may be aliphatic oraromatic compounds. Preferred sulfonic acids/sulfonates contain 2 or 3carboxyl groups and, with inclusion of the carboxyl groups, 3 to 6carbon atoms. A particularly preferred sulfonic acid is sulfosuccinicacid.

In a preferred embodiment, the sulfonic and carboxylic acids arearomatic or aliphatic compounds which carry one or more acid functions.

Particularly preferred esters, partial esters and acid derivatives thuscorrespond to the formulae (3) to (14)

in which R¹, R², R³, R⁵, m, k, x, y and n have the abovementionedmeanings, M is an alkali metal ion, an ammonium ion or H⁺ and B is analiphatic or aromatic group having 1 to 50 carbon atoms, which may alsocontain hetero atoms.

The partial esters according to the invention can be prepared byreacting the copolymers of the formula 1 with suitable acids. However,it should be ensured that the acids do not have an oxidizing effect,since otherwise oxidation of the double bond may take place. For thisreason, the preparation of a sulfate partial ester is preferably carriedout using amidosulfonic acid instead of sulfuric acid. The ammoniumsalts thus obtained can be converted into the corresponding alkali metalsalts by reaction with alkali metal hydroxides. For the preparation ofpartial esters of phosphoric acid, phosphoric acid can be used. Organicacids can be reacted directly, as esters or in the form of anhydrides,with the copolymers of the formula 1. The introduction of functionalgroups is preferably effected after the preparation of the partial esterof the unfunctionalized acids. Thus, the preparation of methacrylicesters, for example of those according to formula 7, can be effected bydirect esterification or transesterification with methacrylic acid ormethyl methacrylate, and the preparation of sulfosuccinic esters, forexample of those according to formula 5, can be effected by preparationof the corresponding maleic esters and subsequent sulfonation, e.g. withpyrosulfites.

The preparation of the sulfonic acids, carboxylic acids and phosphonicacids is effected by reacting the copolymers of the formula 1 with thecorresponding alkanols, halides or cyclic esters of the sulfonic orcarboxylic acids.

The copolymers according to the invention are suitable ascopolymerizable emulsifiers in emulsion polymerization if they containgroups capable of free radical polymerization, i.e. preferablyolefinically unsaturated groups. When used as emulsifiers in emulsionpolymerization, the copolymers according to the invention arepolymerized with further monomers, from which it is intended to preparea polymer dispersion. Unsaturated monomers are suitable for thepreparation of polymer dispersions. Examples of preferred olefinicallyunsaturated monomers are

-   -   vinyl monomers, such as carboxylic esters of vinyl alcohol, for        example vinyl acetate or vinyl propionate, vinyl ethers of        isononanoic acid or of isodecanoic acid,    -   aryl-substituted olefins, such as styrene and stilbene,    -   olefinically unsaturated carboxylic esters, such as methyl        acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate,        isobutyl acrylate, pentyl acrylate, hexyl acrylate, 2-ethylhexyl        acrylate, hydroxyethyl acrylate and the corresponding        methacrylic esters,    -   olefinically unsaturated dicarboxylic esters, such as dimethyl        maleate, diethyl maleate, dipropyl maleate, dibutyl maleate,        dopentyl maleate, dihexyl maleate and di-2-ethylhexyl maleate,    -   olefinically unsaturated carboxylic acids and dicarboxylic        acids, such as acrylic acid, methacrylic acid, itaconic acid,        maleic acid and fumaric acid and their sodium, potassium and        ammonium salts,    -   olefinically unsaturated sulfonic acids and phosphonic acids and        their alkali metal and ammonium salts, such as        acrylamidomethylpropanesulfonic acid and its alkali metal and        ammonium, alkylammonium and hydroxyalkylammonium salts,        allylsulfonic acid and its alkali metal and ammonium salts,        acryloyloxyethylphosphonic acid and its ammonium and alkali        metal salts and the corresponding methacrylic acid derivatives,    -   olefinically unsaturated amines, ammonium salts, nitriles and        amides, such as dimethylaminoethyl acrylate,        acryloyloxyethyltrimethylammonium halides, acrylonitrile,        N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide,        N-methylolacrylamide and the corresponding methacrylic acid        derivatives and vinylmethylacetamide.

In a preferred embodiment, the abovementioned monomers are polymerizedwith further comonomers, preferably olefins or halogenated olefinshaving 2 to 8 carbon atoms, such as, for example, ethylene, propene,butenes, pentenes, 1,3-butadiene, chloroprene, vinyl chloride,vinylidene chloride, vinylidene fluoride and tetrafluoroethylene.

For the preparation of the polymer dispersions, the water-immisciblemonomers are generally finely distributed with the aid of the copolymersaccording to the invention in the aqueous phase in the form of micelles,and the free radical polymerization reaction is initiated by initiatorssuch as, for example, ammonium, sodium and potassium peroxodisulfate.

Further auxiliaries and additives for use with the copolymers accordingto the invention may be protective colloids, such ascarboxymethylcellulose, hydroxyethylcellulose,methylhydroxypropylcellulose and partly and completely hydrolyzedpolyvinyl alcohol.

An overview of customary processes, surfactants and further auxiliariesof emulsion polymerization is given by Peter A. Lovell and Mohamed S.El-Aasser, in “Emulsion Polymerization and Emulsion Polymers”, publishedby John Wiley & Sons, 1997.

The copolymers according to the invention are initially introduced intothe reaction vessel before the beginning of the polymerization reactionor are added to the polymerization vessel during the polymerizationreaction.

In general, the copolymers according to the invention are used asemulsifiers in amounts of from 0.1 to 50, preferably from 0.2 to 10, inparticular from 0.4 to 4% by weight, based on the weight of theolefinically unsaturated monomers which are insoluble or slightlysoluble in water and used for the preparation of the polymer dispersion.

The copolymers according to the invention may be used both alone and incombination with other already known anionic and nonionic emulsifiers ofthe prior art, as described at the outset. The amount of the anionic andnonionic emulsifiers of the prior art is then preferably from 0.001 to5, in particular from 0.01 to 1% and particularly preferably from 0.02to 0.4% by weight, based on the weight of the olefinically unsaturatedmonomers which are insoluble or slightly soluble in water.

The polymer dispersions prepared using the copolymers according to theinvention exhibit little coagulum formation during and after thepolymerization and an improvement in the shear, heat and storagestability, in the freezing/thawing stability and in the electrolytestability compared with divalent and trivalent cations, such as calcium,barium and aluminum. Furthermore, an improvement of the film propertiesof the polymer films produced from the polymer dispersions isobservable. The polymer dispersions prepared using the copolymersaccording to the invention form films having low water absorption,little tarnishing on contact with water, a small contact angle relativeto water and good wet and dry rub fastnesses.

EXAMPLES

Preparation of Copolymers of Alkylene Oxides and Styrene Oxide

Example 1 Allyl Alcohol-initiated Ethylene Oxide/Styrene OxideCopolymer, MW about 1300 g/mol

1 mol of allyl alcohol was partially reacted with 0.1 mol of sodiummethanolate in a laboratory autoclave to give the alcoholate. Methanolwas distilled off. 4 mol of styrene oxide were added dropwise andstirring was effected for 15 hours at 90° C. 20 mol of ethylene oxidewere then added to the reaction product at 140° C. After the ethyleneoxide had completely reacted, the product was analyzed by means of NMRspectroscopy and determination of OH number.

The OH number was 42 mg KOH/g.

The NMR spectrum corresponded to the following structure:

where m=3.8 and k=19, i.e. the ratio of the aromatic protons to thealkenyl and CH₂—OH and the chain CH₂—CH₂—O protons was 19:3:2:76.

Example 2 Methyldiglycol-initiated Styrene Oxide/Ethylene OxideCopolymer

1 mol of methyldiglycol was partially reacted with 0.1 mol of potassiummethanolate in a laboratory autoclave to give the alcoholate. Methanolwas distilled off. 4 mol of styrene oxide were then added dropwise andpolymerization was effected for 5 hours at about 140° C. under pressure.40 mol of ethylene oxide were added to this reaction product at 140° C.After the ethylene oxide had completely reacted, the product wasanalyzed by means of NMR spectroscopy and determination of OH number.

The OH number was 27.9 mg KOH/g.

The NMR spectrum corresponded to the following structure:

where m=3.8 and k=39, i.e. the ratio of the aromatic protons to the CH₃,the CH₂—OH and the chain CH₂—CH₂—O protons was 19:3:2:156.

Example 3 Monoethylene Glycol-initiated Styrene Oxide/Propylene OxideCopolymer

1 mol of monoethylene glycol was partially reacted with 0.1 mol ofpotassium methanolate in a laboratory autoclave to give the alcoholate.Methanol was distilled off. 10 mol of styrene oxide were then added andpolymerization was effected for 5 hours at about 100° C. under pressure.20 mol of propylene oxide were added dropwise to this reaction product,and polymerization was effected again for 9 hours at 130° C. underpressure. After the propylene oxide had completely reacted, the productwas analyzed by means of NMR spectroscopy and determination of OHnumber.

The OH number was 54 mg KOH/g, corresponding to an average molar mass of2080 g/mol, assuming 2 free OH groups per molecule. The NMR spectrumshowed a ratio of CHOH:aromatic styryl:CH₃-propyl protons of 1:23:28,corresponding to the following structure where m=2.3 and k=9.3:

Example 4 Hydroxybutylvinyl-initiated Ethylene Oxide/Styrene OxideCopolymer, MW 2600 g/mol

1 mol of hydroxybutylvinyl ether was partially reacted with 0.1 mol ofpotassium methanolate in an inert solvent (monoglyme) in a laboratoryautoclave to give the alcoholate. Methanol was distilled off.Thereafter, 5 mol of styrene oxide were added and polymerization waseffected for 5 hours at about 100° C. 40 mol of ethylene oxide at 140°C. were added to this reaction product under pressure at 140° C. Afterthe ethylene oxide had completely reacted, the product was analyzed bymeans of NMR spectroscopy and determination of OH number.

The OH number was 24 mg KOH/g.

The NMR spectrum corresponded to the following structure:

where n=4.8 and m=38.Preparation of Esters and Partial Esters

EXAMPLES Example 5

11.4 g of amidosulfonic acid and 0.5 g of 50% strength hypophosphorousacid were added to 150 g of the copolymer from example 1 under nitrogen.The mixture was heated to 80° C. for 5 h and to 100° C. for 1 h withthorough stirring. After the end of the reaction, the mixture wasallowed to cool, and 1.6 g of 20% strength NaOH were added. 158 g (98%)of the sulfuric monoester were obtained.

Example 6

46.6 g of amidosulfonic acid and 0.8 g of urea were added to 500 g ofthe copolymer from example 3 under nitrogen and the mixture was stirredthoroughly for 3 h at 100° C. After the end of the reaction, the mixturewas allowed to cool and 1.5 g of 20% strength NaOH were added. 535 g(98%) of the sulfuric ester were obtained.

Example 7

200 g of the ammonium salt of the sulfuric monoester prepared in example5 were heated to 60° C. At 200 mbar, 32 g of 18% strength NaOH wereadded dropwise and then reacted for a further 2 h at 50 mbar, the waterintroduced being expelled together with the ammonia. 196 g (98%) of thesodium salt of the sulfuric monoester were obtained.

Example 8

24 g of amidosulfonic acid and 0.7 g of urea were added to 500 g of thecopolymer from example 2 under nitrogen and the mixture was thoroughlystirred for 8 h at 120° C. After the end of the reaction, the mixturewas allowed to cool, and 1.2 g of 20% strength NaOH were added. 51 g(99%) of the sulfuric monoester were obtained.

Example 9

2010 g of the copolymer from example 3 were added dropwise to 98 g ofmaleic anhydride at 70° C. under nitrogen. The mixture was then heatedto 90° C. for 4 h and added to a mixture of 52 g of sodium pyrosulfite,40 g of NaOH and 2270 g of distilled water and reacted for 5 h at 80° C.4470 g of sulfosuccinate solution having a content of 50% by weight wereobtained.

Example 10

600 g of the copolymer from example 2 were heated to 100 to 150° C. with50 g of methacrylic acid, 5 g of sulfuric acid and 0.3 g ofphenothiazine. During this procedure, the pressure was slowly reduced to50 mbar and the water of reaction was distilled off. After 12 hours, thereaction was complete. 595 g (95%) of the corresponding methacrylicester were obtained.

Example 11

113 g of polyphosphoric acid were added to 1260 g of the copolymer fromexample 1 at 70° C. and the mixture was stirred for 2 h at 70° C. Aftera further 2 h at 100° C., 30 g of water were added at 90° C. andstirring was effected for a further 2 h. 1400 g of product wereobtained, said product being a mixture of 82% by weight of phosphoricmonoester and 8% by weight of phosphoric diester, and the remainderbeing water. The product contained no phosphoric triester.

Preparation of Sulfonic Acids

EXAMPLES Example 12

174 g of 4-hydroxybenzenesulfonic acid sodium salt dihydrate and 30 g ofNaOH prills were added to 946 g of copolymer from example 1 undernitrogen at 50° C. and the mixture was stirred for 1 h. The mixture wasthen stirred for a further 2 h at 70° C. The lower phase was discardedand the upper phase was neutralized with 7 g of acetic acid. 1025 g(95%) of the desired sulfonic acid ether were obtained.

Example 13

11 g of sodium hydroxide prills were added to 650 g of the alcohol fromexample 4 and drying was effected for 2 hours at 100° C. in vacuo.Thereafter, 0.25 mol (34 g) of butane sulfone was added dropwise undernitrogen at 90° C. and stirring was effected for 6 hours. Theα-vinyloxy-Ω-sulfonate/ethylene oxide/styrene oxide block copolymer wasobtainable in a 70% yield according to NMR analysis.

The NMR spectrum corresponded to the following structure:

Preparation of Carboxylic Acids

EXAMPLES Example 14

59 g of chloroacetic acid sodium salt and 20 g of NaOH prills were addedto 630 g of the copolymer from example 1 under nitrogen at 50° C. andthe mixture was stirred for 3 h. The mixture was then stirred for afurther 4 h at 70° C. The lower phase was discarded and the upper phasewas neutralized with 6 g of acetic acid. 650 g (97%) of the desiredcarboxylic acid ether were obtained.

Example 15

120 g of 4-hydroxybenzoic acid sodium salt and 30 g of NaOH prills wereadded to 1505 g of copolymer from example 2 under nitrogen at 50° C. andthe mixture was stirred for 1 h. The mixture was then stirred for afurther 2 h at 80° C. The lower phase was discarded and the upper phasewas neutralized with 10 g of acetic acid. 1525 g (95%) of the desiredcarboxylic acid ether were obtained.

Preparation of Polymer Dispersions

Example 16 Styrene/Acrylate Dispersion

1020 g of a monomer emulsion consisting of 330.4 g of demineralizedwater, 8.8 g of ®Emulsogen EPA 073 (sodium alkylpolyethylene glycolether sulfate, Clariant GmbH), 10.6 g of the sulfonic acid etheraccording to the invention and from example 11, 3.6 of sodiumbicarbonate, 216 g of styrene, 300 g of n-butyl acrylate, 144 g ofmethyl methacrylate and 6.6 g of methacrylic acid and an initiatorsolution consisting of 3.33 g of ammonium peroxodisulfate and 85.5 ml ofdemineralized water were prepared.

189.1 g of demineralized water were initially introduced into a 2 literreaction vessel and 22 g of Emulsogen EPA 073 were added. The emulsifiersolution in the reaction vessel was heated to 80° C. under a nitrogenatmosphere and while stirring with an anchor stirrer. 22.2 ml ofinitiator solution and 25.5 ml of the monomer emulsion were then added.The free radical polyaddition reaction begins. By means of a water bath,the reaction mixture was cooled and was kept constant at 79-81° C. Theremaining 994.5 g of the monomer emulsion and 66.6 g of the initiatorsolution were added over a period of 3 hours. Thereafter, the reactionmixture was kept at 80° C. for a further hour by means of the water bathand was then cooled to room temperature. The pH of the prepared polymerdispersion was adjusted to pH 7-8 with 12.5% strength ammonia solution.

The resulting polymer dispersion has a solids content of 52% and acoagulum content of <0.05% over a 100 μm sieve and of <0.07% over a 40μm sieve, based on the dispersion.

Example 17 Styrene/Acrylate Dispersion

The procedure was as in example 15. Instead of 10.6 g of the sulfonicacid ether according to the invention and from example 11, 10.6 g of theα-vinyloxy-Ω-sulfonate/ethylene oxide/styrene oxide block copolymeraccording to the invention and from example 12 were used.

The resulting polymer dispersion has a solids content of 52% and acoagulum content of <0.05% over a 100 μm sieve and of <0.07% over a 40μm sieve, based on the dispersion.

Example 18 Styrene/Acrylate Dispersion

1020 g of a monomer emulsion consisting of 332.2 g of demineralizedwater, 4.4 g of Emulsogen EPA 073, 13.2 g of the reactive, nonionicemulsifier according to the invention and from example 4, 3.6 g ofsodium bicarbonate, 216 g of styrene, 300 g of n-butyl acrylate, 144 gof methyl methacrylate and 6.6 g of methacrylic acid and an initiatorsolution consisting of 3.33 g of ammonium peroxodisulfate and 85.5 ml ofdemineralized water were prepared.

193.6 g of demineralized water were initially introduced into a 2 literreaction vessel, and 17.6 g of Emulsogen EPA 073 were added. The furtherprocedure was as in example 15.

The resulting polymer dispersion has a solids content of 52% and acoagulum content of <0.05% over a 100 μm sieve and of <0.1% over a 40 μmsieve, based on the dispersion.

Example 19 Styrene/Acrylate Dispersion

The procedure was as in example 17. Instead of 13.2 g of the reactive,nonionic emulsifier according to the invention and from example 4, 13.2g of the reactive, nonionic emulsifier according to the invention andfrom example 1 were used.

The resulting polymer dispersion has a solids content of 52% and acoagulum content of <0.05% over a 100 μm sieve and of <0.1% over a 40 μmsieve, based on the dispersion.

Example 20 Pure Acrylate Dispersion

1120 g of a monomer emulsion consisting of 247.3 g of demineralizedwater, 5.98 g of Emulsogen EPA 073, 16.8 g of the sulfonic acid etheraccording to the invention and from example 11, 1.37 g of dodecylmercaptan, 93.4 g of methyl methacrylate, 217.9 g of 2-ethylhexylacrylate, 529.2 g of n-butyl acrylate and 8.72 g of methacrylic acid and35.5 g of an initiator solution consisting of 4.44 g of ammoniumperoxodisulfate and 31.06 g of demineralized water were prepared.

163.9 g of demineralized water were initially introduced into a 2 literreaction vessel and heated to 80° C. over a water bath under a nitrogenatmosphere. Thereafter, 10.58 g of the initiator solution were added andthe continuous addition of 1120 g of monomer emulsion and of theremaining 35.5 g of initiator solution was immediately begun. Themetering of the two components was effected with continuous stirringwith an anchor stirrer and under a nitrogen atmosphere within a periodof 3 hours. Thereafter, the reaction mixture was thermostated at 80° C.for a further hour and then cooled to room temperature. The pH of theprepared polymer dispersion was adjusted to pH 7-8 with 12.5% strengthammonia solution.

The resulting polymer dispersion had a solids content of 65% and acoagulum content of <0.05% over a 100 μm sieve and of <0.1% over a 40 μmsieve, based on the dispersion.

Example 21 Pure Acrylate Dispersion

1120 g of a monomer emulsion consisting of 247.3 g of demineralizedwater, 5.98 g of Emulsogen EPA 073, 16.81 g of theα-vinyloxy-Ω-sulfonate/ethylene oxide/styrene oxide block copolymeraccording to the invention and from example 12, 1.37 g of dodecylmercaptan, 93.4 g of methyl methacrylate, 217.9 g of 2-ethylhexylacrylate, 529.2 g of n-butyl acrylate and 8.72 g of methacrylic acid and35.5 g of an initiator solution consisting of 4.44 g of ammoniumperoxodisulfate and 31.06 g of demineralized water were prepared.

163.9 g of demineralized water were initially introduced into a 2 literreaction vessel and heated to 80° C. over a water bath under a nitrogenatmosphere. The further procedure was as in example 19.

The resulting polymer dispersion had a solids content of 65% and acoagulum content of <0.05% over a 100 μm sieve and of <0.1% over a 40 μmsieve, based on the dispersion.

Example 22 Pure Acrylate Dispersion

1120 g of a monomer emulsion consisting of 251.3 g of demineralizedwater, 18.8 g of the sulfuric monoester according to the invention andfrom example 8, 1.37 g of dodecyl mercaptan, 93.4 g of methylmethacrylate, 217.9 g of 2-ethylhexyl acrylate, 529.2 g of n-butylacrylate and 8.72 g of methacrylic acid and 35.5 g of an initiatorsolution consisting of 4.44 g of ammonium peroxodisulfate and 31.06 g ofdemineralized water were prepared.

163.9 g of demineralized water were initially introduced into a 2 literreaction vessel and heated to 80° C. over a water bath under a nitrogenatmosphere. The further procedure was as in example 19.

The resulting polymer dispersion had a solids content of 65% and acoagulum content of <0.05% over a 100 μm sieve and of <0.1% over a 40 μmsieve, based on the dispersion.

1. A method for emulsion polymerization, said method comprising adding acopolymer of the formula (1)

in which R¹ is hydrogen, a C₁-C₅-alkyl radical, or C₂-C₅-alkenyl radicalwhich may also contain hetero atoms, an acid group or an aliphatic oraromatic group having 1 to 50 carbon atoms, including an acid group, R²and R³, independently of one another, are hydrogen, methyl and/or ethyl,n is a number from 0 to 100, and m is a number from 3 to 30, and k is anumber from 1 to 200, and A is a copolymer unit of the formula (2)

in which R⁴ is hydrogen, a C₁-C₅-alkyl radical or C₂-C₅-alkenyl radicalwhich may also contain hetero atoms, an acid group or an aliphatic oraromatic group having 1 to 50 carbon atoms, including an acid group, R⁵is hydrogen, methyl and/or ethyl, x is a number from 0 to 100, and y isa number from 3 to 30, where R¹ is hydrogen or an acid group, via thevalence denoted by “*”, to a polymer reaction mixture and polymerizingsaid mixture.
 2. The method of claim 1, wherein the alkoxy groups arearranged block by block.
 3. The method of claim 1, wherein k is a numberfrom 10 to
 100. 4. The method of claim 1, wherein m is a number from 3to
 10. 5. The method of claim 1, wherein n is a number from 1 to
 5. 6.The method of claim 1, wherein formula 1 represents an ester or partialester.
 7. The method of claim 1, wherein R¹ or R⁴ is a C₂- to C₅-alkenylgroup.
 8. The method of claim 1, further comprising admixing a pigmentor a bitumen with the copolymer prior to said polymerization to emulsifysaid pigment or bitumen.